Extension Springs Music Wire
SPEC extension springs have a wide application for experimental, development, prototype and maintenance work and have been specified and designed to high precision standards.
| Part Number | CAD | D0 (mm) | d (mm) | L0 (mm) | L1 (mm) | P (N) | T (N) | R (N/mm) | Qty / Price |
|---|---|---|---|---|---|---|---|---|---|
| E00630070250M |  |
1.60 | 0.18 | 6.35 | 13.72 | 1.423 | 0.13 | 0.18 | |
| E00630070310M | |
1.60 | 0.18 | 7.87 | 18.54 | 1.423 | 0.13 | 0.12 | |
| E00630070380M | |
1.60 | 0.18 | 9.65 | 23.62 | 1.423 | 0.13 | 0.09 | |
| E00630070440M | |
1.60 | 0.18 | 11.18 | 28.45 | 1.423 | 0.13 | 0.07 | |
| E00630070500M | |
1.60 | 0.18 | 12.70 | 33.27 | 1.423 | 0.13 | 0.07 | |
| E00630080250M | |
1.60 | 0.20 | 6.35 | 11.68 | 2.00 | 0.18 | 0.35 | |
| E00630080310M | |
1.60 | 0.20 | 7.87 | 15.24 | 2.00 | 0.18 | 0.25 | |
| E00630080380M | |
1.60 | 0.20 | 9.65 | 19.05 | 2.00 | 0.18 | 0.19 | |
| E00630080440M | |
1.60 | 0.20 | 11.18 | 23.11 | 2.00 | 0.18 | 0.16 | |
| E00630080500M | |
1.60 | 0.20 | 12.70 | 26.67 | 2.00 | 0.18 | 0.12 | |
| E00630080620M | |
1.60 | 0.20 | 15.75 | 34.04 | 2.00 | 0.18 | 0.11 | |
| E00630080750M | |
1.60 | 0.20 | 19.05 | 41.66 | 2.00 | 0.18 | 0.09 | |
| E00630090250M | |
1.60 | 0.23 | 6.35 | 10.16 | 2.76 | 0.27 | 0.65 | |
| E00630090310M | |
1.60 | 0.23 | 7.87 | 13.21 | 2.76 | 0.27 | 0.47 | |
| E00630090380M | |
1.60 | 0.23 | 9.65 | 16.51 | 2.76 | 0.27 | 0.37 | |
| E00630090440M | |
1.60 | 0.23 | 11.18 | 19.56 | 2.76 | 0.27 | 0.30 | |
| E00630090500M | |
1.60 | 0.23 | 12.70 | 22.86 | 2.76 | 0.27 | 0.25 | |
| E00630090620M | |
1.60 | 0.23 | 15.75 | 28.70 | 2.76 | 0.27 | 0.19 | |
| E00630090750M | |
1.60 | 0.23 | 19.05 | 35.56 | 2.76 | 0.27 | 0.16 | |
| E00630110250M | |
1.60 | 0.28 | 6.35 | 8.64 | 4.85 | 0.44 | 1.94 |
EXTENSION SPRINGS
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MATERIALS
‘E’ part numbers
Music wire: ASTM A228 or AMS 5112
‘T’ part numbers
Music wire: DIN 17223 or JIS G4314 A313 SWP-A/B or AMS 5112
TOLERANCES
‘E’ part numbers
Outside Diameter
1.45 to 3.02mm ± 0.08mm
3.05 to 6.10mm ± 0.13mm
6.12 to 12.70mm ± 0.20mm
12.73 to 25.40mm ± 0.38mm
25.43 to 31.12mm +/-0.51mm
31.14 to 37.08mm +/-0.76mm
37.11 to 50.08mm +/-1.02mm
Load P +/- 10%
Spring Rate R +/- 10%
‘T’ part numbers
All dimension and forces to DIN 2097 (Grade 2)
ADDITIONAL TECHNICAL DATA
All SPEC extension springs have uniform body diameter and are produced with full twist loops the same diameter as the body. They are wound with initial tension, therefore some force is required before the coils are initially separated.
ENDS
German style closed loop. End position may vary. Special ends are available on request.
LOADS
Initial tension T is for reference only and will vary. To determine the load at any working length use the formula:
P = (rate x deflection) + Initial Tension
1lb = 4.448 Newtons
1 Newton = 0.225 lb
SURFACE FINISH
Music wire - oiled.
Shot-peened and plated finishes supplied on request.
Allow sufficient additional time for special finishes.
Key of Measurements
Do = Outside diameter
d = Wire diameter
Lo = Free length (reference use only inside hooks)
L1 = Maximum extended length
P = Load at L1
T = Initial tension
R = Spring rate
Initial tension is for reference only and may
